WO2016072514A1

WO2016072514A1 - Method for producing polyalkylene glycol, viscosity index improver, lubricating oil composition, and method for producing lubricating oil composition

Info

Publication number: WO2016072514A1
Application number: PCT/JP2015/081395
Authority: WO
Inventors: 妙子中野; 忠氣仙
Original assignee: 出光興産株式会社
Priority date: 2014-11-07
Filing date: 2015-11-06
Publication date: 2016-05-12
Also published as: EP3216816A4; CN107075107A; KR20170084052A; EP3216816A1; US20170355818A1; JPWO2016072514A1

Abstract

This method for producing polyalkylene glycol comprises polymerizing an alkylene oxide using a composite metal catalyst and producing a polyalkylene glycol, wherein the polymerization reaction is carried out in the presence of 10-90 mass% of organic solvent relative to the polyalkylene glycol to be produced.

Description

Method for producing polyalkylene glycol, viscosity index improver, lubricating oil composition, and method for producing lubricating oil composition

The present invention relates to a method for producing a polyalkylene glycol (hereinafter also referred to as PAG) using a composite metal catalyst, a viscosity index improver and a lubricating oil composition using the PAG produced by this production method, and a lubricating oil composition The present invention relates to a method for manufacturing a product.

PAG is widely used as a raw material for polyurethane products such as elastomers, adhesives and sealants, and functional oils. Generally, PAG is produced by addition polymerization of an alkylene oxide such as ethylene oxide and propylene oxide to an initiator having an active hydrogen atom such as various alcohols.

Alkali catalysts are widely used as addition polymerization catalysts. In addition, in the case of an alkali catalyst, an unsaturated alcohol is produced by a side reaction, which becomes an initiator, so that it is difficult to produce a PAG having a molecular weight of more than 6500. Therefore, conventionally, as described in Patent Document 1, for example, a method for producing PAG using a double metal cyanide complex as a catalyst has been attempted. When a double metal cyanide complex is used, the production of unsaturated alcohol due to side reactions can be suppressed, and a relatively high molecular weight PAG can be produced.
For example, Patent Document 2 discloses that when a double metal cyanide complex is used as a catalyst, an organic solvent is allowed to coexist in the reaction system in order to suppress an increase in viscosity of the obtained PAG. Here, since the method disclosed in Patent Document 2 is based on the premise that the organic solvent is removed, the addition of the organic solvent is considered in consideration of the ease of removing the organic solvent and the effect of suppressing the increase in viscosity. The amount is 5% by mass or less.

U.S. Pat. No. 3,278,458 Japanese Patent No. 2946580

However, using the method described in Patent Document 2, for example, if an attempt is made to produce a high molecular weight PAG having a molecular weight exceeding 10,000, the reaction solution becomes too viscous in the latter half of the reaction, making stirring difficult and the reaction rate. However, there is room for further improvement in terms of efficiently producing a high molecular weight PAG.
Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a production method capable of efficiently producing even a high molecular weight PAG.

As a result of intensive studies, the inventors of the present invention have produced the above-mentioned problem by setting the blending ratio of the organic solvent within a certain range in the method for producing a polyalkylene glycol (PAG) by polymerizing alkylene oxide using a composite metal catalyst. As a result, the present invention has been completed. That is, according to one aspect of the present invention, the following [1] to [4] are provided.
[1] In a method for producing a polyalkylene glycol by polymerizing an alkylene oxide using a composite metal catalyst, a polymerization reaction is carried out in the presence of 10 to 90% by mass of an organic solvent with respect to the produced polyalkylene glycol. A method for producing alkylene glycol.
[2] A viscosity index improver containing a polyalkylene glycol having a weight average molecular weight of 20000 or more obtained by the production method according to [1].
[3] A lubricating oil composition comprising the polyalkylene glycol produced by the production method according to [1] above.
[4] A method for producing a lubricating oil composition, which comprises blending a mixture containing the polyalkylene glycol produced by the production method according to [1] and the organic solvent to obtain a lubricating oil composition.

According to the present invention, a high molecular weight polyalkylene glycol can be efficiently produced by the presence of an organic solvent at a predetermined ratio in the polymerization reaction.

Hereinafter, the present invention will be described using embodiments.
The method for producing a polyalkylene glycol (PAG) according to the present embodiment comprises producing a polyalkylene glycol by polymerizing alkylene oxide using a composite metal catalyst in the presence of an organic solvent.

<Composite metal catalyst>
As the composite metal catalyst used in the polymerization reaction, a composite metal cyanide complex catalyst is preferable. The double metal cyanide complex catalyst preferably contains an organic ligand. As the organic ligand, various compounds described later can be used, but an alcohol compound is preferably used.
Specific examples of the double metal cyanide complex catalyst include those having the following general formula (1).
M _a [M ′ _x (CN) _y ] _b (H ₂ O) _c (R) _d (1)
However, M is Zn (II), Fe (II), Fe (III), Co (II), Ni (II), Al (III), Sr (II), Mn (II), Cr (III), Cu (II), Sn (II), Pb (II), Mo (IV), Mo (VI), W (IV), W (VI), etc., and M ′ is Fe (II), Fe (III), Co (II), Co (III), Cr (II), Cr (III), Mn (II), Mn (III), Ni (II), V (IV), V (V), etc., and R is It is an organic ligand, a, b, x and y are positive integers that vary depending on the metal valence and coordination number, and c and d are positive numbers that vary depending on the metal coordination number.

In the general formula (1), M is preferably Zn (II), and M ′ is preferably Fe (II), Fe (III), Co (II), Co (III) or the like. Examples of the organic ligand include a ketone compound, an ether compound, an aldehyde compound, an ester compound, an alcohol compound, and an amide compound, and an alcohol compound is preferable. As the alcohol compound, t-butyl alcohol, n-butyl alcohol, sec-butyl alcohol, iso-butyl alcohol, tert-pentyl alcohol, iso-pentyl alcohol, and the like can be used. Alcohol is preferred.

The double metal cyanide complex represented by the general formula (1) includes a metal salt MX _a (M, a is an anion that forms a salt with M as described above) and a polycyanometalate (salt) Z _e [M ' _x (CN) _y ] _f (In this formula, M', x and y are the same as described above. Z is hydrogen, alkali metal, alkaline earth metal, etc., e and f are the valences of Z and M '. (A positive integer determined by the order) of each aqueous solution or a mixed solvent of water and an organic solvent, and the resulting double metal cyanide complex is brought into contact with the compound that forms the organic ligand R. It is produced by removing the solvent and the compound that forms the organic ligand R.
The polycyanometalate (salt) Z _e [M ′ _x (CN) _y ] _f may be any of various metals including hydrogen and alkali metals for Z, but lithium salt, sodium salt, potassium salt Magnesium salts and calcium salts are preferred. Particularly preferred are the usual alkali metal salts, i.e. sodium and potassium salts.
Moreover, the double metal cyanide complex represented by the general formula (1) can be made into a slurry by mixing with a part of the initiator described later. Therefore, it may be handled in the form of a slurry by mixing with a part of the initiator while contacting with the compound forming the organic ligand or after contacting with the compound forming the organic ligand.

<Organic solvent>
In this embodiment, the polymerization reaction is performed in the presence of 10 to 90% by mass of an organic solvent with respect to the produced polyalkylene glycol (PAG). In the present embodiment, by setting the organic solvent to 10% by mass or more, it is possible to prevent the viscosity of the reaction liquid from increasing during the reaction, and it is possible to easily polymerize the produced PAG. Moreover, it becomes possible to manufacture high molecular weight PAG efficiently by setting it as 90 mass% or less. From the above viewpoint, the organic solvent is preferably present in a proportion of 30 to 70% by mass with respect to the produced PAG.

Examples of the organic solvent used in this embodiment include ether compounds. By using an ether compound, it can be suitably used as a base oil when blended in a lubricating oil composition without removing the organic solvent. Examples of the ether compound include monoether, diether, polyether, polyvinyl ether, and polyalkylene glycol ether.
Examples of monoethers include dialkyl ethers in which the alkyl group is a branched or straight chain alkyl group having 1 to 12 carbon atoms, particularly preferably 5 to 12 carbon atoms. Specific examples include di-2-ethylhexyl ether, Symmetric ethers such as di-3,5,5-trimethylhexyl ether; and asymmetric ethers such as 2-ethylhexyl-n-octyl ether and 3,5,5-trimethylhexyl-n-nonyl ether. By using an alkyl group having 5 to 12 carbon atoms, it can be more suitably used as a base oil when blended in a lubricating oil composition without removing the organic solvent.
As the diether, dialkyl diether is used, and more specifically, diethers of various diols are used. As the diol, linear or branched alkanediols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, and neopentyl glycol can be used. As the polyether, alkyl ethers of trihydric or higher polyhydric alcohols such as glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and dipentaerythritol can be used.
In addition, the dialkyl ether and the alkyl ether of the polyhydric alcohol are those in which the alkyl group is a branched or straight chain alkyl group having 1 to 12 carbon atoms, particularly preferably 5 to 12 carbon atoms, like the monoether. It can be used. Moreover, the alkyl group of a diether and a polyether may be used individually or may be used in mixture of several types. By using an alkyl group having 5 to 12 carbon atoms, it can be more suitably used as a base oil when blended in a lubricating oil composition without removing the organic solvent.

These monoethers, diethers, and polyethers preferably have a molecular weight of 150 to 5,000, more preferably 200 to 3,000. These organic solvents can be suitably used as a base oil when the produced PAG is blended in a lubricating oil composition without removing the organic solvent as described later by setting the molecular weight in the above range. The polymerization reaction in the embodiment can be appropriately advanced.

Examples of the polyvinyl ether used as the organic solvent include polyvinyl ether having a branched or straight chain alkyl group having 1 to 4 carbon atoms in the side chain, and polyvinyl ether having a polyoxyalkylene structure in the side chain.
Examples of these polyvinyl ethers include polyvinyl compounds having a structural unit represented by the following general formula (2) as a repeating unit.

R ^1a in the general formula (2) represents a divalent hydrocarbon group having 2 to 4 carbon atoms. Specific examples include an ethylene group, a propylene group, and a butylene group, with a propylene group being preferred. R ^2a is an alkyl group having 1 to 4 carbon atoms, specifically, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert group -A butyl group is exemplified, but an ethyl group and an isobutyl group are preferable.
In the general formula (2), r represents the number of repetitions, and the average value is a number in the range of 0 to 10, preferably 0 to 5.
In addition, the terminal structure of polyvinyl ether is not particularly limited, but one having no active hydrogen atom such as a hydroxyl group is used so as not to react with alkylene oxide.
Moreover, what is necessary is just to select suitably the repeating number of the structural unit represented by the said General formula (2) according to the molecular weight desired.

As the polyalkylene glycol ether used as the organic solvent, a polyalkylene glycol having a terminal hydroxyl group etherified with a linear or branched alkyl group having 1 to 5 carbon atoms is used. The polyalkylene glycol ether can be appropriately used as an organic solvent because the terminal hydroxyl group is etherified with an alkyl group and thus does not react with the alkylene oxide.

The polyalkylene glycol ether used as the organic solvent is represented, for example, by the following general formula (3).
R ^1b [— (OR ^2b ) _m —OR ^3b ] _n (3)
(Wherein R ^1b is an alkyl group having 1 to 5 carbon atoms, a hydrocarbon group having 1 to 10 carbon atoms having 2 to 6 bonds, or an oxygen-containing hydrocarbon group having 1 to 10 carbon atoms, and R ^2b is An alkylene group having 2 to 4 carbon atoms, R ^3b is an alkyl group having 1 to 5 carbon atoms, n is an integer of 1 to 6, and m is a number with an average value of m × n of 6 to 80.

In the general formula (3), the alkyl group in each of R ^1b and R ^3b specifically includes a methyl group, an ethyl group, an n-propyl group, an isopropyl group, various linear or branched butyl groups, various types And a linear or branched pentyl group. When R ^1b and R ^3b are alkyl groups, they may be the same as or different from each other. Further, when n is 2 or more, a plurality of R ^{3b in} one molecule may be the same or different.

Further, when R ^1b is a hydrocarbon group having 1 to 10 carbon atoms having 2 to 6 bonding sites, the hydrocarbon group may be a chain or a cyclic one. . The hydrocarbon group having two bonding sites is preferably an aliphatic hydrocarbon group, for example, ethylene group, propylene group, butylene group, pentylene group, hexylene group, heptylene group, octylene group, nonylene group, decylene group, cyclopentylene group. Examples thereof include a len group and a cyclohexylene group.
Further, the hydrocarbon group having 3 to 6 binding sites is preferably an aliphatic hydrocarbon group, for example, trimethylolpropane, glycerin, pentaerythritol, sorbitol, 1,2,3-trihydroxycyclohexane, 1,3,3, Examples thereof include a residue obtained by removing a hydroxyl group from a polyhydric alcohol such as 5-trihydroxycyclohexane. Furthermore, examples of the oxygen-containing hydrocarbon group having 1 to 10 carbon atoms in R ^1b include a chain aliphatic group having an ether bond and a cyclic aliphatic group (for example, a tetrahydrofurfuryl group).
R ^2b in the general formula (3) is an alkylene group having 2 to 4 carbon atoms, and examples of the oxyalkylene group of the repeating unit include an oxyethylene group, an oxypropylene group, and an oxybutylene group. Further, n is preferably 1 to 3, and more preferably 1.

The organic solvent may be removed after completion of the reaction, but can be used without being removed. If the organic solvent is not removed, for example, when the produced PAG is blended in the lubricating oil composition, the organic solvent is also blended in the lubricating oil composition as a base oil.
Among the above, the organic solvent is preferably polyvinyl ether or polyalkylene glycol ether because it is more suitable as a base oil. In addition, polyvinyl ether and polyalkylene glycol ether are preferable from the viewpoint that the produced PAG is easily dissolved as compared with other ethers.
The polyvinyl ether and polyalkylene glycol ether used as the organic solvent described above preferably have a weight average molecular weight of 200 to 5,000, more preferably 200 to 3,000. By setting it as the range of the said molecular weight, these compounds can be used more suitably as base oil, and it becomes possible to advance a polymerization reaction appropriately.

<Alkylene oxide>
The above polymerization reaction is usually allowed to proceed by the presence of a catalyst in a mixture of an alkylene oxide and an initiator in the presence of an organic solvent.
The alkylene oxide is a monoepoxide, specifically, an alkylene oxide having 2 to 4 carbon atoms, and more specifically, ethylene oxide, propylene oxide, butylene oxide. Among these, Ethylene oxide and propylene oxide are preferred.

<Initiator>
The initiator may be a compound having one or more hydroxyl groups, and may be selected according to the structure of the PAG to be produced. The alkyl group is a linear or branched alkyl group having 1 to 10 carbon atoms. Divalent alkyl alcohols; branched or straight chained alkanes having about 2 to 10 carbon atoms, such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, etc. Alkanediols: Trimethylolpropane, glycerin, pentaerythritol, sorbitol, 1,2,3-trihydroxycyclohexane, 1,3,5-trihydroxycyclohexane, and other trihydric or higher polyhydric alcohols having about 3 to 10 carbon atoms And a polyalkylene glycol having a weight average molecular weight lower than that of the PAG produced in this embodiment. Lumpur but (hereinafter, also referred to as a low molecular weight PAG) may be mentioned. Among them, in that more can be efficiently manufacture of PAG of a high molecular weight, low molecular weight PAG is more preferable.

Examples of the low molecular weight PAG used as the initiator include polyalkylene glycols represented by the following general formula (4).
R ^1C- (OR ^2C ) _k -OH (4)
In the general formula (4), k represents a number having an average value of 2 to 80. R ^1C represents an alkyl group having 1 to 5 carbon atoms or a hydrogen atom, R ^2C represents an alkylene group having 2 to 4 carbon atoms, and ^examples of the oxyalkylene group of the repeating unit include an oxyethylene group and an oxypropylene group. And oxybutylene group.
The weight average molecular weight of the low molecular weight PAG is not particularly limited, but is preferably 1000 to 20000, more preferably 2000 to 20000.

In the general formula (4), the oxyalkylene groups in one molecule may be the same or two or more oxyalkylene groups may be contained, but 50 mol% or more oxypropylene is contained in one molecule. What contains a unit is more preferable, and what contains 75 mol% or more of oxypropylene units is more preferable. More preferably, all of OR ^2C are oxypropylene groups. R ^1C is preferably a hydrogen atom.
Among them, polypropylene glycol (PPG) in which all of OR ^2C is an oxypropylene group and R ^1C is a hydrogen atom is more preferable.

Although the specific method of the said polymerization reaction is not specifically limited, For example, it is preferable to react, gradually adding an alkylene oxide to the reaction container previously charged with the initiator, the catalyst, and the organic solvent. However, a part or all of the organic solvent may be added to the reaction vessel together with the alkylene oxide instead of being charged into the reaction vessel in advance.
The reaction temperature is not particularly limited, but is preferably 80 to 150 ° C, more preferably 100 to 130 ° C.

Moreover, the pressure at the time of performing a polymerization reaction is not specifically limited, You may carry out under a normal pressure, and you may carry out under pressure. When performing under pressure, the method of raising an internal pressure by adding alkylene oxide to the sealed reaction container, for example is mentioned.
The amount of the catalyst used is not particularly limited, but about 1 to 5000 ppm is appropriate for the initiator used. As described above, the catalyst may be introduced into the reaction vessel all at once as described above, or may be charged in divided portions.
The amount of alkylene oxide fed into the reaction vessel is not particularly limited, but is usually 160 to 5000 equivalents, preferably 300 to 5000 equivalents, more preferably 300 to 3500 equivalents, relative to the initiator used. .

The polymerization reaction can be stopped, for example, by adding a catalyst deactivator. Examples of the catalyst deactivator include alkali metal compounds, and more specifically sodium alkoxides such as sodium methoxide. After deactivating the catalyst, the reaction solution is neutralized with an acidic substance, and then appropriately post-treated and purified, and the deactivated catalyst component is removed from the reaction solution.
The reaction liquid from which the catalyst has been removed consists of a mixture containing PAG produced by the polymerization reaction and an organic solvent. Although the organic solvent may be removed from this mixture, it is preferable not to remove the organic solvent from the viewpoint of production efficiency.

Further, the PAG produced by the above polymerization reaction has a hydroxyl group at the terminal, but the terminal hydroxyl group may be further blocked by etherification or esterification depending on the application. Since the terminal hydroxyl group is hardly hydrolyzed, it is preferably blocked by etherification.
For example, in the case of end-capping by etherification, etherification is preferably performed with a linear or branched alkyl group having 1 to 10 carbon atoms, preferably a linear or branched alkyl group having 1 to 5 carbon atoms. In the case of esterification, it is preferable to esterify with various fatty acids having about 1 to 10 carbon atoms.

In the present embodiment, as described above, even when a PAG having a molecular weight of 20000 or more is used by using a double metal cyanide complex catalyst and an organic solvent and making the amount of the organic solvent used within a certain range, the efficiency is high. Can be manufactured well.

[How to use the manufactured PAG]
The PAG obtained by the above production method can be used for lubricating oil, for example. As described above, the PAG produced in the present embodiment is obtained as a mixture with an organic solvent. However, when used in a lubricating oil application, the PAG is preferably used without removing the organic solvent from the mixture. By using the organic solvent without removing it, it is possible to prevent the PAG from increasing in viscosity and to facilitate handling. In addition, the number of steps can be reduced by not removing the organic solvent. Furthermore, since the organic solvent becomes a base oil in the lubricating oil composition, the organic solvent can be effectively used.
That is, the lubricating oil composition according to one embodiment of the present invention includes the PAG produced above, but the lubricating oil composition is obtained by blending a mixture containing the produced PAG and an organic solvent. Is preferred. In this case, since the organic solvent is not removed as described above, the organic solvent is contained in the mixture in an amount of 10 to 90% by mass, preferably 30 to 70% by mass, based on the produced PAG. It is contained in the ratio.
The lubricating oil composition is usually obtained by further blending base oil and various additives other than PAG or the above mixture.

In addition, the PAG produced above is usually used as a viscosity index improver in a lubricating oil composition. The viscosity index improver is added to the lubricating oil composition to improve the viscosity index of the lubricating oil composition. In particular, as described above, a high molecular weight PAG (having a weight average molecular weight of preferably 20000 or more, more preferably 30000 or more) has a large effect of improving the viscosity index, and can be more suitably used as a viscosity index improver.
Of course, when the produced PAG is used as a viscosity index improver, a PAG obtained by removing the solvent from the above mixture and purifying may be used as the viscosity index improver. It is preferable to use the mixture (for example, as above-mentioned, the mixture containing PAG and an organic solvent) as a viscosity index improver.

The lubricating oil composition is used, for example, as a lubricating oil composition for a refrigerator that is used by being filled in a refrigerator together with a refrigerant. Specifically, a compressor provided in the refrigerator, etc. It is used to lubricate the sliding part.
In addition to the refrigerator, the lubricating oil composition is used in internal combustion engines such as gasoline engines and diesel engines, transmissions, shock absorbers, various gear structures, various bearing mechanisms, and other various industrial devices. May be.

Further, the PAG obtained by the above production method can be used in various applications other than the lubricating oil application, and may be used in applications such as a sealant and an adhesive. In this case, the produced PAG may be used without removing the organic solvent from the mixture containing the PAG and the organic solvent, or may be used after being removed. The PAG obtained by this production method can be used as a raw material for polymer materials such as urethane constituting elastomers, resins, rubbers, etc., and for applications such as sealants and adhesives, it is a raw material for urethane. It is preferable to be used as

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

The physical properties were determined according to the following procedure.
(1) Weight average molecular weight (Mw)
The weight average molecular weight was measured using gel permeation chromatography (GPC). GPC was measured using a TSKgel SuperMultipore HZ-M manufactured by Tosoh Corporation as a column, tetrahydrofuran as an eluent, a refractive index detector as a detector, and a weight average molecular weight as a standard sample polystyrene.

[Preparation of composite metal complex catalyst]
An aqueous solution consisting of 10.2 g of zinc chloride and 10 g of water was placed in a 500 ml flask. Next, an aqueous solution composed of 4.3 g of potassium hexacyanocobaltate and 75 g of water was added dropwise to the flask over 30 minutes while the inside of the flask was stirred and maintained at 40 ° C. After completion of the dropwise addition, the mixture in the flask was further stirred for 30 minutes, and then a mixture consisting of 80 g of tert-butyl alcohol, 80 g of water, and 0.6 g of polypropylene glycol having a weight average molecular weight of 2000 (both end hydroxyl groups) was further added to the flask. And stirred at 40 ° C. for 30 minutes and then at 60 ° C. for 60 minutes. The mixture thus obtained was subjected to pressure filtration using a circular filter plate having a diameter of 125 mm and a quantitative filter paper for fine particles to separate a slurry-like solid containing a double metal cyanide complex catalyst.
Next, the obtained solid was transferred to a flask, a mixture of 36 g of tert-butyl alcohol and 84 g of water was added and stirred for 30 minutes, and then pressure filtration was performed to obtain a slurry-like solid. The obtained solid was transferred to a flask, a mixture of 108 g of tert-butyl alcohol and 12 g of water was further added and stirred for 30 minutes, and a liquid in which the double metal cyanide complex catalyst was dispersed in the tert-butyl alcohol-water mixed solvent was added. Obtained. After 120 g of polypropylene glycol having a weight average molecular weight of 2000 (both terminal hydroxyl groups) as an initiator was added to and mixed with this liquid, the volatile components were distilled off under reduced pressure at 80 ° C. for 3 hours and further at 115 ° C. for 3 hours. A mixture comprising an initiator and a double metal cyanide complex catalyst was obtained.

[Example 1]
[Manufacture of PAG]
In a 200 ml autoclave, 10.05 g of a mixture of an initiator and a double metal cyanide complex catalyst (polypropylene glycol: 10 g, double metal cyanide complex catalyst 0.05 g), and polyethyl vinyl ether (weight average molecular weight: 362) as an organic solvent 28 g (30% by mass with respect to the manufactured PAG) was charged. After the inside of the autoclave was purged with nitrogen, 40 g of propylene oxide was added, and the internal temperature was raised to 130 ° C. After confirming that the pressure in the autoclave was lowered, 43 g of propylene oxide was added at a flow rate of 3 ml / min. After the addition, the reaction was continued until the internal temperature was maintained at 130 ° C. and the pressure in the autoclave was 0.1 MPa or less. After the reaction, 1.5 g of sodium methoxide as a catalyst deactivator was added, stirred for 1 hour, 1N sulfuric acid was added in an amount of 1.5 times equivalent to sodium, neutralized at 120 ° C. for 2 hours, and then stirred at 120 ° C. for 2 hours. After dehydration for a period of time, filtration was performed. After filtration, 2.0 wt% of synthetic magnesium silicate was added as an adsorbent, treated at 120 ° C. for 30 minutes, dehydrated at 20 Torr for 2 hours, filtered, and PAG produced by the above reaction (92 g) And 120 g of a mixture with an organic solvent was obtained. Only the PAG was extracted from the obtained mixture, and the weight average molecular weight Mw of the PAG was measured by the method described above. The Mw was 30000.

[Example 2]
It implemented similarly to Example 1 except the point which made the quantity of the organic solvent used by a polymerization reaction 65 g, and set the usage-amount to 70 mass% with respect to PAG manufactured. Only the PAG was extracted from the obtained mixture, and the weight average molecular weight Mw of the PAG was measured by the method described above. The Mw was 30000.

[Example 3]
It implemented similarly to Example 1 except the point which made the quantity of the organic solvent used by a polymerization reaction into 46 g, and set the usage-amount to 50 mass% with respect to PAG manufactured. Only the PAG was extracted from the obtained mixture, and the weight average molecular weight Mw of the PAG was measured by the method described above. The Mw was 30000.
[Example 4]
The amount of the organic solvent used in the polymerization reaction was 30 g, the amount used was 30% by mass with respect to the produced PAG, and 15.08 g of a mixture composed of an initiator and a double metal cyanide complex catalyst (polypropylene glycol) : 15 g, double metal cyanide complex catalyst 0.08 g). Only the PAG was extracted from the obtained mixture, and the weight average molecular weight Mw of the PAG was measured by the method described above. The Mw was 20000.

[Comparative Example 1]
The polymerization reaction was carried out in the same manner as in Example 1 except that the solvent was not used. Similarly to Example 1, after all the propylene oxide was added, the reaction was carried out while maintaining the internal temperature at 130 ° C., but the stirring blade stopped during the reaction, making it difficult to continue the polymerization reaction.

[Comparative Example 2]
The polymerization reaction was carried out in the same manner as in Example 1 except that the amount of the organic solvent used in the polymerization reaction was 4.6 g, so that the amount used was 5% by mass with respect to the produced PAG. .
Similarly to Example 1, after all the propylene oxide was added, the reaction was carried out while maintaining the internal temperature at 130 ° C., but the stirring blade stopped during the reaction, and it was difficult to continue the polymerization reaction.

[Comparative Example 3]
It carried out similarly to Example 1 except the point which made the amount of the organic solvent used by a polymerization reaction 88 mass% with respect to PAG manufactured by using 88 g. In Comparative Example 3, the reaction time was long and the polymerization was not completed.

As described above, in each of Examples 1 to 3, a high molecular weight PAG could be efficiently produced by carrying out the polymerization reaction in the presence of 10 to 90% by mass of an organic solvent. On the other hand, in Comparative Examples 1 and 2 in which the amount of the organic solvent was less than 10% by mass, the viscosity became too high during the reaction to stop the reaction, and a high molecular weight PAG could not be produced efficiently. Further, as in Comparative Example 3, when the amount of the organic solvent exceeded 90% by mass, the polymerization was not completed even if the reaction time was prolonged, and a high molecular weight PAG could not be produced efficiently.

The polyalkylene glycol produced in the present invention is blended in a lubricating oil composition used for a refrigerator, an internal combustion engine, a gear structure, a bearing mechanism, a transmission, a shock absorber, and the like, and is used as, for example, a viscosity index improver. Is. It can also be used as a raw material for urethane constituting adhesives, sealants and the like.

Claims

In a method for producing a polyalkylene glycol by polymerizing alkylene oxide using a composite metal catalyst, a polyalkylene glycol is subjected to a polymerization reaction in the presence of 10 to 90% by mass of an organic solvent with respect to the produced polyalkylene glycol. Production method.
The method for producing a polyalkylene glycol according to claim 1, wherein the organic solvent is an ether compound.
A dialkyl ether in which the ether group is a branched or straight chain alkyl group having 5 to 12 carbon atoms; a dialkyl diether in which the alkyl group is a branched or straight chain alkyl group having 5 to 12 carbon atoms; A polyether which is an alkyl ether of a trihydric or higher polyhydric alcohol which is a branched or linear alkyl group having 5 to 12 carbon atoms; a polyvinyl ether; and a terminal hydroxyl group having a linear or branched carbon number of 1 to 5 The process for producing a polyalkylene glycol according to claim 2, wherein the polyalkylene glycol ether is etherified with an alkyl group.
The production of polyalkylene glycol according to claim 3, wherein the ether compound is selected from polyvinyl ether; and a polyalkylene glycol ether in which a terminal hydroxyl group is etherified with a linear or branched alkyl group having 1 to 5 carbon atoms. Method.
The method for producing a polyalkylene glycol according to any one of claims 1 to 4, wherein the composite metal catalyst is a composite metal cyanide complex catalyst.
The method for producing a polyalkylene glycol according to claim 5, wherein the double metal cyanide complex catalyst contains an alcohol compound as an organic ligand.
The polyalkylene glycol is produced by polymerizing the mixture of the alkylene oxide and the initiator in the presence of a composite metal catalyst, and the initiator is a compound having one or more hydroxyl groups. The manufacturing method of the polyalkylene glycol in any one of.
The method for producing a polyalkylene glycol according to claim 7, wherein the compound having one or more hydroxyl groups is a polyalkylene glycol having a weight average molecular weight lower than that of the produced polyalkylene glycol.
The method for producing a polyalkylene glycol according to any one of claims 1 to 8, wherein a polyalkylene glycol having a weight average molecular weight of 20000 or more is produced.
A viscosity index improver comprising a polyalkylene glycol produced by the production method according to claim 9.
A lubricating oil composition comprising a polyalkylene glycol produced by the production method according to any one of claims 1 to 9.
A method for producing a lubricating oil composition, wherein a lubricating oil composition is obtained by blending a mixture containing the polyalkylene glycol produced by the production method according to any one of claims 1 to 9 and the organic solvent.